From nobody Sun Feb 8 10:05:26 2026 Received: from wxsgout04.xfusion.com (wxsgout03.xfusion.com [36.139.52.80]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 292851E3DE5 for ; Wed, 29 Oct 2025 04:01:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=36.139.52.80 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761710514; cv=none; b=Z5mlbY9moLQSR32ajBQskjkgHlUY7XWAuiMuU8NocMzfHTJ0xHLArmfHpvdXSexTo+H0DDOVBtMbbWt+schjPOafd19vNFhoMU8HucCI4naPtl4a9TbDwTFqo4CTRZ4/9K6FTejj18z6Ixe/RBvfkFHomYp5/lFbGnCNK+OMJ4U= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761710514; c=relaxed/simple; bh=LKDLCtaCIHQ/NgSHufRUIv43r+UKoK+Ay+P1wDPYaTw=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=JJ9i/eEJFV0c3yvd+8oqKDsz32giyRlyiTJd5puPJms8GwK9dDO0rqCVPbyc4ncH3i1qYbsaISp6qjSstSgz6VgXJNr2IGF2smHRbbBY2+YSH9TxH0z6MJyQgwD//mcQI/YIsxxIF02tXNDVCsORTnqH42+8BXvD12fAoDXM6DM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=xfusion.com; spf=pass smtp.mailfrom=xfusion.com; arc=none smtp.client-ip=36.139.52.80 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=xfusion.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=xfusion.com Received: from wuxpheds03048.xfusion.com (unknown [10.32.143.30]) by wxsgout04.xfusion.com (SkyGuard) with ESMTPS id 4cxCnv6KrhzB661H; Wed, 29 Oct 2025 11:45:55 +0800 (CST) Received: from DESKTOP-Q8I2N5U.xfusion.com (10.82.130.100) by wuxpheds03048.xfusion.com (10.32.143.30) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_RSA_WITH_AES_128_CBC_SHA256) id 15.2.2562.20; Wed, 29 Oct 2025 11:46:30 +0800 From: shechenglong To: , , CC: , , , , , shechenglong Subject: [PATCH v2 1/2] cpu:Remove the print when the CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY Kconfig option is disabled. Date: Wed, 29 Oct 2025 11:45:53 +0800 Message-ID: <20251029034554.1839-2-shechenglong@xfusion.com> X-Mailer: git-send-email 2.37.1.windows.1 In-Reply-To: <20251029034554.1839-1-shechenglong@xfusion.com> References: <20250918064907.1832-1-shechenglong@xfusion.com> <20251029034554.1839-1-shechenglong@xfusion.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: wuxpheds03046.xfusion.com (10.32.128.186) To wuxpheds03048.xfusion.com (10.32.143.30) Content-Type: text/plain; charset="utf-8" Following the pattern established with other Spectre mitigations, do not prints a message when the CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY Kconfig option is disabled. Link: https://patchwork.kernel.org/project/linux-arm-kernel/patch/202509180= 64907.1832-1-shechenglong@xfusion.com/ Suggested-by: Will Deacon Signed-off-by: shechenglong --- arch/arm64/kernel/proton-pack.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/arm64/kernel/proton-pack.c b/arch/arm64/kernel/proton-pac= k.c index f9a32dfde006..d833b7c1bba8 100644 --- a/arch/arm64/kernel/proton-pack.c +++ b/arch/arm64/kernel/proton-pack.c @@ -1042,8 +1042,6 @@ void spectre_bhb_enable_mitigation(const struct arm64= _cpu_capabilities *entry) if (arm64_get_spectre_v2_state() =3D=3D SPECTRE_VULNERABLE) { /* No point mitigating Spectre-BHB alone. */ - } else if (!IS_ENABLED(CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY)) { - pr_info_once("spectre-bhb mitigation disabled by compile ti= me option\n"); } else if (cpu_mitigations_off() || __nospectre_bhb) { pr_info_once("spectre-bhb mitigation disabled by command li= ne option\n"); } else if (supports_ecbhb(SCOPE_LOCAL_CPU)) { -- 2.33.0 From nobody Sun Feb 8 10:05:26 2026 Received: from wxsgout04.xfusion.com (wxsgout03.xfusion.com [36.139.52.80]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2921B13AD26 for ; Wed, 29 Oct 2025 04:01:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=36.139.52.80 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761710514; cv=none; b=ZpxTqxXLT4VQFsIjTH5LZp5PPx1y9r4Rh3usJyEhjZbspdwr8C+tbcBveAzJGKNrU1qXvtUTbH80/PVw7w4AEOw/uyBlTruHzk7yYydML/rIDlOevJ7cyQcV4i1DHAGGE7AfSTdbZPIr/SDeRUvcfqAKhLoRGnMWQPDSGPqox2M= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761710514; c=relaxed/simple; bh=BcRZ6hb4eWUgJMud/DQ/wdKbE9i3yZNlpMW21cd/wUg=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=SBh5DpWPZTBRb1u+CK0LmyQiimdeglDrTrgGbqPqWgVanKCVdhkPBB1Z/CiUGgES4YISNWjuHCYFlJkgXX2PWHE6GQcBzJt+8NDBAViNCJ6T0NMyPFVCEwxOuFHkb9MsxTsvYKsXY2Uycml0BCsS/MCjLdMIGMqPt2ogtX1eNJo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=xfusion.com; spf=pass smtp.mailfrom=xfusion.com; arc=none smtp.client-ip=36.139.52.80 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=xfusion.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=xfusion.com Received: from wuxpheds03048.xfusion.com (unknown [10.32.143.30]) by wxsgout04.xfusion.com (SkyGuard) with ESMTPS id 4cxCny5MCSzB90fq; Wed, 29 Oct 2025 11:45:58 +0800 (CST) Received: from DESKTOP-Q8I2N5U.xfusion.com (10.82.130.100) by wuxpheds03048.xfusion.com (10.32.143.30) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_RSA_WITH_AES_128_CBC_SHA256) id 15.2.2562.20; Wed, 29 Oct 2025 11:46:32 +0800 From: shechenglong To: , , CC: , , , , , shechenglong Subject: [PATCH v2 2/2] cpu: fix hard lockup triggered by printk calls within scheduling context Date: Wed, 29 Oct 2025 11:45:54 +0800 Message-ID: <20251029034554.1839-3-shechenglong@xfusion.com> X-Mailer: git-send-email 2.37.1.windows.1 In-Reply-To: <20251029034554.1839-1-shechenglong@xfusion.com> References: <20250918064907.1832-1-shechenglong@xfusion.com> <20251029034554.1839-1-shechenglong@xfusion.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: wuxpheds03046.xfusion.com (10.32.128.186) To wuxpheds03048.xfusion.com (10.32.143.30) Content-Type: text/plain; charset="utf-8" relocate the printk() calls from spectre_v4_mitigations_off() and spectre_v2_mitigations_off() into setup_system_capabilities() function, preventing hard lockups that occur when printk() is invoked from scheduler = context. Link: https://patchwork.kernel.org/project/linux-arm-kernel/patch/202509180= 64907.1832-1-shechenglong@xfusion.com/ Suggested-by: Mark Rutland Suggested-by: Catalin Marinas Suggested-by: Will Deacon Signed-off-by: shechenglong --- arch/arm64/include/asm/spectre.h | 2 ++ arch/arm64/kernel/cpufeature.c | 7 ++++++- arch/arm64/kernel/proton-pack.c | 28 ++++++++++++++-------------- 3 files changed, 22 insertions(+), 15 deletions(-) diff --git a/arch/arm64/include/asm/spectre.h b/arch/arm64/include/asm/spec= tre.h index 8fef12626090..f244b52fb123 100644 --- a/arch/arm64/include/asm/spectre.h +++ b/arch/arm64/include/asm/spectre.h @@ -118,5 +118,7 @@ void spectre_bhb_patch_wa3(struct alt_instr *alt, void spectre_bhb_patch_clearbhb(struct alt_instr *alt, __le32 *origptr, __le32 *updptr, int nr_ins= t); +void spectre_print_disabled_mitigations(void); + #endif /* __ASSEMBLY__ */ #endif /* __ASM_SPECTRE_H */ diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 5ed401ff79e3..6836e314fd30 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -94,7 +94,7 @@ #include #include #include - +#include /* Kernel representation of AT_HWCAP and AT_HWCAP2 */ static DECLARE_BITMAP(elf_hwcap, MAX_CPU_FEATURES) __read_mostly; @@ -3875,6 +3875,11 @@ static void __init setup_system_capabilities(void) */ if (system_uses_ttbr0_pan()) pr_info("emulated: Privileged Access Never (PAN) using TTBR= 0_EL1 switching\n"); + + /* + * Report Spectre mitigations status. + */ + spectre_print_disabled_mitigations(); } void __init setup_system_features(void) diff --git a/arch/arm64/kernel/proton-pack.c b/arch/arm64/kernel/proton-pac= k.c index d833b7c1bba8..386f986e6b5d 100644 --- a/arch/arm64/kernel/proton-pack.c +++ b/arch/arm64/kernel/proton-pack.c @@ -91,12 +91,7 @@ early_param("nospectre_v2", parse_spectre_v2_param); static bool spectre_v2_mitigations_off(void) { - bool ret =3D __nospectre_v2 || cpu_mitigations_off(); - - if (ret) - pr_info_once("spectre-v2 mitigation disabled by command lin= e option\n"); - - return ret; + return __nospectre_v2 || cpu_mitigations_off(); } static const char *get_bhb_affected_string(enum mitigation_state bhb_state) @@ -421,13 +416,8 @@ early_param("ssbd", parse_spectre_v4_param); */ static bool spectre_v4_mitigations_off(void) { - bool ret =3D cpu_mitigations_off() || + return cpu_mitigations_off() || __spectre_v4_policy =3D=3D SPECTRE_V4_POLICY_MITIGATION_= DISABLED; - - if (ret) - pr_info_once("spectre-v4 mitigation disabled by command-lin= e option\n"); - - return ret; } /* Do we need to toggle the mitigation state on entry to/exit from the ker= nel? */ @@ -1042,8 +1032,6 @@ void spectre_bhb_enable_mitigation(const struct arm64= _cpu_capabilities *entry) if (arm64_get_spectre_v2_state() =3D=3D SPECTRE_VULNERABLE) { /* No point mitigating Spectre-BHB alone. */ - } else if (cpu_mitigations_off() || __nospectre_bhb) { - pr_info_once("spectre-bhb mitigation disabled by command li= ne option\n"); } else if (supports_ecbhb(SCOPE_LOCAL_CPU)) { state =3D SPECTRE_MITIGATED; set_bit(BHB_HW, &system_bhb_mitigations); @@ -1197,3 +1185,15 @@ void unpriv_ebpf_notify(int new_state) pr_err("WARNING: %s", EBPF_WARN); } #endif + +void spectre_print_disabled_mitigations(void) +{ + if (spectre_v2_mitigations_off()) + pr_info("spectre-v2 mitigation disabled by command-line opt= ion\n"); + + if (spectre_v4_mitigations_off()) + pr_info("spectre-v4 mitigation disabled by command-line opt= ion\n"); + + if (__nospectre_bhb || cpu_mitigations_off()) + pr_info("spectre-bhb mitigation disabled by command-line op= tion\n"); +} -- 2.33.0